diff --git a/core/control/HTTPRequest.php b/core/control/HTTPRequest.php
index 18987c0c9..d77e4f362 100755
--- a/core/control/HTTPRequest.php
+++ b/core/control/HTTPRequest.php
@@ -342,7 +342,7 @@ class SS_HTTPRequest implements ArrayAccess {
 				if($varRequired && !isset($this->dirParts[$i])) return false;
 				
 				$arguments[$varName] = isset($this->dirParts[$i]) ? $this->dirParts[$i] : null;
-				if($part == '$Controller' && (!ClassInfo::exists($arguments['Controller']) || !ClassInfo::is_subclass_of($arguments['Controller'], 'RequestHandler'))) {
+				if($part == '$Controller' && (!ClassInfo::exists($arguments['Controller']) || !ClassInfo::is_subclass_of($arguments['Controller'], 'Controller'))) {
 					return false;
 				}